• Title/Summary/Keyword: LeeWhang

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Design of Management Information Base for SNMP-based Power Line Communication System Applicable to Railway Vehicles (철도 차량 간 통신에 적용 가능한 SNMP 기반 전력선 통신 시스템의 운영 정보 베이스 설계)

  • An, Jin-Ung;Lee, Jae-Ho;Cho, Whang;Lee, Key-Seo
    • Journal of the Korean Society for Railway
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    • v.11 no.1
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    • pp.69-74
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    • 2008
  • This paper presents the design and implementation of MIB for SNMP-based PLC system which is applicable to communication for railway vehicles. The proposed MIB has four nodes which are "Basic Information", "Configuration", "Stats", and "Alarm." The essential peripheral functions for "Alarm" to improve the performance of PLC are deyised. ACF is for auto connecting devices without intervention of the user. DEC is for checking the loss of data and the presence of error. DLPF is for preventing the loss of data and error To evaluate the proposed system, the experimental set-up is developed and the experiments are successfully carried out. The conclusion points out that the suggested MIB contributes the betterment of the conventional PLC systems.

Sensitivity Analysis and Parameter Estimation of Activated Sludge Model Using Weighted Effluent Quality Index (가중유출수질지표를 이용한 활성오니공정모델의 민감도 분석과 매개변수 보정)

  • Lee, Won-Young;Kim, Min-Han;Kim, Young-Whang;Lee, In-Beum;Yoo, Chang-Kyoo
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.11
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    • pp.1174-1179
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    • 2008
  • Many modeling and calibration methods have been developed to analyze and design the biological wastewater treatment process. For the systematic use of activated sludge model (ASM) in a real treatment process, a most important step in this usage is a calibration which can find a key parameter set of ASM, which depends on the microorganism communities and the process conditions of the plants. In this paper, a standardized calibration protocol of the ASM model is developed. First, a weighted effluent quality index(WEQI) is suggested far a calibration protocol. Second, the most sensitive parameter set is determined by a sensitive analysis based on WEQI and then a parameter optimization method are used for a systematic calibration of key parameters. The proposed method is applied to a calibration problems of the single carbon removal process. The results of the sensitivity analysis and parameter estimation based on a WEQI shows a quite reasonable parameter set and precisely estimated parameters, which can improve the quality and the efficiency of the modeling and the prediction of ASM model. Moreover, it can be used for a calibration scheme of other biological processes, such as sequence batch reactor, anaerobic digestion process with a dedicated methodology.

Nucleophilic Substitution Reactions of α-Bromoacetanilides with Benzylamines

  • Adhikary, Keshab Kumar;Kim, Chan-Kyung;Lee, Bon-Su;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.191-196
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    • 2008
  • Kinetic studies of the reactions of a-bromoacetanilides [YC6H4NHC(=O)CH2Br] with substituted benzylamines (XC6H4CH2NH2) have been carried out in dimethyl sulfoxide at 35.0 oC. The Hammett plots for substituent (Y) variations in the substrate (log kN vs. sY) are biphasic concave upwards/downwards with breaks at Y = 4-Cl (sY = 0.23). The Hammett coefficients rY and the cross-interaction constant rXY (= +0.16) are positive for sY 0.23, while the rY values are positive/negative [rY > 0 for X = (4-MeO and 4-Me) and rY < 0 for X = (H, 4-Cl and 3-Cl)] and the rXY (= -1.51) value is negative for sY ³ 0.23. Based on these and other results, the benzylaminolyses of a-bromoacetanilides are proposed to proceed through rate-limiting expulsion of the bromide leaving group from a zwitterionic tetrahedral intermediate, T, with a bridged transition state for s Y 0.23, while the reaction proceeds through concerted mechanism with an enolate-like TS in which the nucleophile attacks the a-carbon for s Y ³ 0.23.

Kinetics and Mechanism of the Addition of Benzylamines to Benzylidene Meldrum's Acids in Acetonitrile

  • Oh, Hyuck-Keun;Kim, Tae-Soo;Lee, Hai-Whang;Lee, Ik-Choon
    • Bulletin of the Korean Chemical Society
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    • v.24 no.2
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    • pp.193-196
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    • 2003
  • Nucleophilic addition reactions of benzylamines $(XC_6H_4CH_2NH_2)$ to benzylidene Meldrum's acids (BMA; $YC_6H_4CH=C(COO)_2C(CH_3)_2$) have been investigated in acetonitrile at 20.0 ℃. The rates of addition are greatly enhanced due to the abnormally high acidity of Meldrum's acid. The magnitudes of the Hammett $({\rho}_X\;and\;{\rho}_Y)$ and Bronsted $({\rho}_X$)$ coefficients are rather small suggesting an early transition state. The sign and magnitude of the cross-interaction constant, ${\rho}_{XY}$ (= -0.33), and kinetic isotope effects $(k_H/k_D\;{\stackrel}{~}{=}\;1.5-1.7)$ involving deuterated benzylamine nucleophilies $(XC_6H_4CH_2ND_2)$ are indicative of hydrogen-bonded cyclic transition state. The activation parameters, ${\Delta}H^{\neq}\;{\stackrel}{~}{=}\;4\;kcal\;mol^{-1}\;and\;{\Delta}S^{\neq}\;{\stackrel}{~}{=}\;-37\;e.u.$, are also in line with the proposed mechanism.

Prevention of Epimerization and Quantitative Determination of Amygdalin in Armeniacae Semen with Schizandrae Fructus Solution

  • Joo, Woo-Sang;Jeong, Ji-Seon;Kim, Hyo-Geun;Lee, Yong-Moon;Lee, Je-Hyun;Hong, Seon-Pyo
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1096-1101
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    • 2006
  • Armeniacae Semen not only contains amygdalin, but emulsin also, which is an enzyme that hydrolyzes amygdalin. The extraction yield of amygdalin from Armeniacae Semen was low, due to the presence of emulsin, when extracted with water. When Schizandrae Fructus solution was used as the extractant; however, amygdalin was almost completely extracted, regardless of the cutting size, due to the absence of the influence of emulsin. In addition, when the crude powder or small piece forms were used with Schizandrae Fructus solution, on epimerization of the D-amygdalin into neoamygdalin occurred. D-amygdalin and its conversion product, neoamygdalin, were quantitatively analyzed by reverse-phase, high-performance liquid chromatography (HPLC), with an optimized eluent of 10 mM sodium phosphate buffer (pH 2.3), containing 11.5% acetonitrile. The concentration and detector response were linearly correlated over the range 0.05 to 2 mM. The detection limits for both D-amygdalin and neoamygdalin were approximately $5\;{\mu}M$ for the amount injected.

A Study on the Dielectric Properties of Glass Fiber-Reinforced Plastic Composites (유리 섬유 강화 복합재료의 유전 특성에 관한 연구)

  • Lee, B.S.;Whang, M.W.;Kim, J.S.;Cho, G.S.;Yuk, J.H.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1615-1617
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    • 1996
  • In this study, epoxidized bisphenolic resins laminated with glass fiber mat(GFRP) are ivestigated on surface, bulk aspect and dielectric constant(${\varepsilon}'$ and ${\varepsilon}''$) vs. frequency characteristics with temperature. The investigation shows the different characteristics accordig to the attachments of fiber surface, filler content, matrix properties, and the others. Especially, dielectric properties of this sample are highly increased above $100^{\circ}C$ and decreased with the rise of frequency. There is a resonance at the high frequency region ($1MHz{\sim}10MHz$). So, dielectric properties show the shift with frequency and temperature. Dielectric properties of EGL 10 are higher than those of EGL 40 with the frequency. Generally, dielectric properties of EGL 10 are more unstable than those of EGL 40 on the shift of frequency and temperature.

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Patent Processus Vaginalis in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis - Two Cases Confirmed by Radionuclide Peritoneal Scintiscan - (복막투석환자에서의 개존된 Processus Vaginalis -방사성핵종복막촬영술로 확진된 2예-)

  • Lee, Jae-Tae;Son, Sang-Kyun;Lee, Kyu-Bo;Whang, Kee-Suk;Cho, Dong-Kyu;Koh, Chul-Woo
    • The Korean Journal of Nuclear Medicine
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    • v.23 no.2
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    • pp.231-236
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    • 1989
  • Continuous ambulatory peritoneal dialysis (CAPD) is a well established method of treating end stage renal failure, and is commonly used as an alternative to hemodialysis. Several complications have been observed. These include catheter malfunction, abdominal and inguinal hernia, and peritonitis. A relatively frequent complication is swelling of external genitalia, due to bowel fluid passing through a patent processus vaginalis. Special diagnostic procedures are necessary to determine the nature of the abnormality and to guide the surgical correction. We reported two cases of patent processus vaginalis in patient on CAPD proved by radionuclide peritoneal scintiscan using Tc-99 m-tin colloid.

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$^{67}Ga-Citrate$ Scan in A Case of Granulocytic Sarcoma with Bone Marrow Remission of Acute Myelogenous Leukemia (관해된 급성 골수성 백혈병 환자에서 발생한 과립성 육종의 $^{67}Ga-citrate$ Scan 소견)

  • Kim, Gwang-Weon;Chung, Byung-Cheon;Lee, Jae-Tae;Lee, Kyu-Bo;Whang, Kee-Suk
    • The Korean Journal of Nuclear Medicine
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    • v.24 no.2
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    • pp.337-342
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    • 1990
  • A case of a 39-year-old man with granulocytic sarcoma documented by positive Ga-67 scan is described and brief review of literature was performed. He was diagnosed as acute myelogenous leukemia and got complete remission with antileukemic chemotherapy for 7 months. On admission, picture of his bone marrow and peripheral blood showed remission state of leukemia. Radiologic examinations were performed for evaluation of lesions in head and chest, and findings of granulocytic sarcoma were suspected. So we got $^{67}Ga-citrate$ scan and pleural biopsy for identification of causes of intractable pleural effusion and skin lesion. Myeloblastomas (or granular sarcomas) proved by pleural biopsy were correctly identified by $^{67}Ga-citrate$ scan, and disease extent was clearly delineated. We believe that $^{67}Ga-scintigraphy$ is very helpful in localizing and follow-up evaluation of granulocytic sarcoma.

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Influence of Solvents on Rates of Reactions of 2,4-Dinitro Substituted Halobenzenes with Substituted Anilines (III) (2,4-이니트로할로벤젠과 치환된 아닐린의 반응속도에 대한 용매효과 (제3보))

  • Hai Whang Lee;Ikchoon Lee
    • Journal of the Korean Chemical Society
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    • v.22 no.4
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    • pp.221-228
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    • 1978
  • Rates of reactions of 2,4-dinitrofluorobenzene and 2,4-dinitrobromobenzene with para substituted anilines in acetonitrile-methanol binary mixtures have been measured. It has been shown that methanol acts as nucleophilic catalyst upon reaction of 2,4-dinitrobromobenzene with anilines and as bifunctional catalyst upon reaction of 2,4-dinitrofluorobenzene with anilines. The electrophilic catalysis by methanol probably consists of formation of hydrogen bond in the transition state between alcoholic hydrogen and leaving group, fluorine. Nucleophilic catalysis by methanol may be ascribed to formation of hydrogen bond between alcoholic oxygen and amine hydrogen in the transition state.

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Kinetics and Mechanism of the Aminolysis of Phenacyl Bromides in Acetonitrile. A Stepwise Mechanism with Bridged Transition State

  • Lee, Ik-Choon;Lee, Hai-Whang;Yu, Young-Kab
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.993-998
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    • 2003
  • In the aminolysis of phenacyl bromides ($YC_6H_4COCH_2Br$) with benzylamines ($XC_6H_4CH_2NH_2$) in acetonitrile, the Bronsted βx (βnuc) values observed are rather low ( βX = 0.69-0.73). These values are similar to those (βx $^~_=$ 0.7) for other aminolysis reactions of phenacyl compounds with anilines and pyridines, but are much smaller than those ( βx = 1.1-2.5) for the aminolysis of esters with benzylamines which are believed to proceed stepwise with rate-limiting expulsion of the leaving group. The relative constancy of the βx values (βx $^~_=$ 0.7) irrespective of the amine, leaving group and solvent can be accounted for by a bridged type transition state in the rate-limiting expulsion of the leaving group. Thus the aminolysis of phenacyl derivatives are proposed to proceed stepwise through a zwitterionic tetrahedral intermediate ($T^{\pm}$), with rate-limiting expulsion of the leaving group from $T^{\pm}$. In the transition state, the amine is bridged between the carbonyl and α-carbons, which leads to negligible effect of amine on the leaving group expulsion rate.